Recently, computer software for use in word processors and home electronics (e.g., video-decks) contains a so-called assist-function or help-function that displays a description of operation of the device whenever a user requests it by pressing a help key. The help function selectively displays help-information in accordance with the operating stage when the user pushed the help key. Thus the user can easily perform any necessary function at any desired time without being acquainted with all steps for operating a system or a device.
In any system having an increasing number of functions, it is rather difficult for the user to find necessary information among a large number of listed items on a display. Therefore, the system is requested to correctly understand a function requested by the user and to display corresponding operation instruction.
Japanese Laid-Open Patent Publication No. 7-121563 discloses a help-information retrieving device that receives a keyword inputted after a Help key operation and retrieves suitable help information from a database by the keyword and displays the found information.
The above-mentioned help-information retrieving device allows the user to carry out an objective function by performing necessary operations according to the instruction displayed. With multiplication of functions to be realized in a system or device, it becomes difficult to design such a system that may realize all functions by simple operations. In other words, the user must carry out a plurality of steps to realize a desired function. The correct procedure for realizing a desired function may be given to the user but is troublesome for the user to do every time.
The above-mentioned help-information retrieving device retrieves information by getting a match of keywords. For example, a word processor having a printing function is given a keyword print, print-out, printing! for retrieving the printing function whenever the user requests it with the keyword "print" or "print-out" or "printing". By matching correctly a keyword-code, it is also possible to design the retrieving system so that it retrieves the printing function by any one of two requests having the same meaning but written in different kinds of characters, e.g., Japanese Hiragana characters and Katakana characters.
With an entered request sentence, e.g., "outputting on paper", the keyword matching type retrieval system extracts keywords outputting, paper! but can not search the printing function because they do not coincide with any one of the keywords print, print-out, printing!. It is difficult to previously register all keywords that users may use in their requests. Thus, the retrieval by keywords has limitations of searching a function that matches the meaning of a requesting sentence entered by the user.